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A Rodríguez

Publications and source records attributed to A Rodríguez.

At least 181 records · Page 10Linked to original sources
PubMed1997

A large-scale evaluation of peptide vaccines against foot-and-mouth disease: lack of solid protection in cattle and isolation of escape mutants.

A large-scale vaccination experiment involving a total of 138 cattle was carried out to evaluate the potential of synthetic peptides as vaccines against foot-and-mouth disease. Four types of peptides representing sequences of foot-and-mouth disease virus (FMDV) C3 Argentina 85 were tested: A, which includes the G-H loop of capsid protein VP1 (site A); AT, in which a T-cell epitope has been added to site A; AC, composed of site A and the carboxy-terminal region of VP1 (site C); and ACT, in which the three previous capsid motifs are colinearly represented. Induction of neutralizing antibodies, lymphoproliferation in response to viral antigens, and protection against challenge with homologous infectious virus were examined. None of the tested peptides, at several doses and vaccination schedules, afforded protection above 40%. Protection showed limited correlation with serum neutralization activity and lymphoproliferation in response to whole virus. In 12 of 29 lesions from vaccinated cattle that were challenged with homologous virus, mutant FMDVs with amino acid substitutions at antigenic site A were identified. This finding suggests the rapid generation and selection of FMDV antigenic variants in vivo. In contrast with previous studies, this large-scale vaccination experiment with an important FMDV host reveals considerable difficulties for vaccines based on synthetic peptides to achieve the required levels of efficacy. Possible modifications of the vaccine formulations to increase protective activity are discussed.

Amino Acid Sequence↗
PubMed1997

Isolation and characterization of promoters from the Lactobacillus casei temperate bacteriophage A2.

Random Sau3A1 DNA fragments from the temperate Lactobacillus bacteriophage A2 were cloned into the promoter-probe plasmid pGKV210. Seven DNA fragments with promoter activity were selected, after transformation of Escherichia coli and Lactococcus lactis, subsp, lactis, through the chloramphenicol resistance they conferred to the corresponding clones. The seven promoters were functional in Lactobacillus casei. Their strength was analysed by measuring the levels of chloramphenicol resistance and chloramphenicol acetyltransferase activity induced in each host. The nucleotide sequences of these fragments were determined and primer extension analysis was used to locate the initiation site of transcription from each promoter in E coli. The promoters contained -10 and -35 regions similar to the consensus sequences of E. coli and Lactobacillus promoters.

Bacteriophages↗
PubMed1997

Free and total PSA in the diagnosis of prostate cancer.

The use of PSA in the diagnosis of prostate cancer is controversial. This is due to false-positive results caused by benign prostatic hyperplasia (BPH). Different forms of circulating PSA have recently been described. Initial studies indicate that the fraction of free PSA is lower in prostate cancer than in BPH, therefore suggesting that its measurement could be of some diagnostic value. We have assessed the serum value of the percentage of free/total PSA in the differential diagnosis of BPH and prostate cancer. The levels of PSA and free PSA (DELFIA) were measured in 145 BPH patients and 56 prostate cancer patients. Free PSA is a small fraction of PSA, and significantly lower levels are being found in prostate cancer. In those patients with a PSA level between 2 and 25 micrograms/l, the determination of the percentage of free PSA increased the diagnostic efficiency of PSA, while reducing the number of negative biopsies. We conclude that free PSA may be a useful marker for the diagnosis of prostate cancer.

Aged↗
PubMed1997

Characterization and selection of lactobacilli isolated from Spanish fermented sausages.

The use of starter cultures to control and run the fermentative process is a usual way of manufacturing sausages in meat industries. The first stage in the starter culture designing process is to characterize the lactic acid bacteria isolated from these meat products, in order to select the best strains. The strains used for this study were isolated from different dry fermented sausages, obtained during the manufacturing process. The main tests used to identify the isolated bacteria were: microscopic-morphologic characteristics, catalase activity, production of gas, growth at 8, 15 and 45 degrees C, fermentation of carbohydrates and production of lactic acid isomers. A total of 194 strains were identified. Lactobacillus sake and Lactobacillus plantarum were the most frequent species. Other microbiological tests were also performed, and three strains of Lactobacillus sake were found which did not produce dextran from sucrose.

Carbohydrate Metabolism↗
PubMed1997

[Rescue angioplasty].

This article resumes the modern management of acute myocardial infarction. It analyzes the complementary benefits of two different types of treatment: thrombolytic therapy and percutaneous transluminal angioplasty.

Angioplasty, Balloon, Coronary↗
PubMed1996

Biochemical and serologic evidence for the existence of functionally distinct forms of the CD94 NK cell receptor.

The CD94 NK cell receptor is assembled as a disulfide-linked dimer and appears to be encoded by a single-copy gene of the C-type lectin superfamily. In reverse Ab-dependent cellular cytotoxicity assays, CD94-specific mAbs may either trigger or inhibit cytotoxicity in distinct subsets of NK clones, termed groups A and B, respectively. The molecular basis for this functional ambivalence of CD94 has been addressed. CD94 molecules immunoprecipitated with the HP-3B1 mAb from the two different subsets of NK clones were comparatively analyzed by SDS-PAGE. Under reducing conditions, the stimulating form of CD94 from group A clones displayed a significantly lower Mr (39 kDa) than the inhibitory form of group B clones (Mr = 43 kDa). Analyses of N-glycanase and V8 protease-digested samples indicated that the two CD94 forms are homologous. A CD94-specific mAb (Z199) that did not recognize cells transfected with a CD94 cDNA (LL288) was characterized. Z199 did not bind to group A clones, whereas its reactivity with group B NK cells was indistinguishable from that of other CD94-specific mAbs. Different from the HP-3B1 mAb, the Z199 mAb displayed only inhibitory effects in reverse Ab-dependent cellular cytotoxicity assays. Immunoprecipitation studies confirmed that Z199 selectively identified the 43-kDa CD94. Our study proves the existence of at least two biochemically and serologically distinct CD94 molecules, whose selective/predominant expression at the clonal level correlates with the pattern of response (i.e., inhibition vs activation) of NK cells to ligation by CD94-specific mAbs.

Antigens, CD↗
PubMed1996

Immunocytochemical detection of growth factors (PDGF and TGF beta) in equine chronic pneumonia.

The roles played by platelet-derived growth factor (PDGF) and transforming growth factor beta (TGF beta) in the development of pulmonary fibrosis in equine chronic pneumonia varied greatly. Macrophages, epithelial cells and fibroblasts were identified as a source of PDGF, the principal role of which was related to its mitotic effect on epithelial cells, and particularly on fibroblasts in the final phase of the disease. TGF beta was detected in epithelial cells in all three phases of the disease and in fibroblasts in the last phase. However, the role of TGF beta in this pulmonary disease is not clear because its expression in the cytoplasm of fibroblasts in areas of strong collagenation during the last phase was weak. Nonetheless, it was responsible for the production and release of collagen during the stage of total fibrosis.

Animals↗
PubMed1996

Influence of vitamin D receptor genotype on bone mass changes after renal transplantation.

Renal transplant patients immunosuppressed with cyclosporine A (CsA) exhibit both a significant bone loss and an increased rate of bone fractures. An association between common allelic variants of the the vitamin D receptor (VDR) gene and bone mineral density and turnover has been reported in adults. However, the genetic influence on the rate of bone loss after renal transplantation has not been explored. We prospectively determined the changes in spinal mineral density in 34 consecutive nondiabetic adults who received a cadaveric renal allograft. Serum biochemical markers of bone metabolism and the vertebral mineral density (VMD) assessed by quantitative computed tomography were determined at the time of transplantation and three and twelve months later. In fifteen patients the histomorphometric features of iliac bone were analyzed at baseline and twelve months after transplantation. VDR alleles were typed by a PCR assay based on a polymorphic BsmI restriction site. Patients with the so-called "favorable" bb genotype (N = 12) were compared with those with the Bb or BB genotype (N = 22). Baseline VMD was similar in patients with or without the favorable bb genotype. Three months after transplantation the mean (+/- SD) VMD decreased 14 +/- 13.3 percent in all patients (16.5 +/- 13.1% in patients homozygous for the b allele and 13.77 +/- 13.9% in those with Bb or BB genotypes). The rate of VMD loss at this time inversely correlated with pretransplant PTH levels (r = -0.40; P < 0.05). Between 3 and 12 months after transplantation, patients with the favorable bb genotype recovered more VMD than those with Bb or BB types and showed a significantly higher Z score at the end of the follow-up (-0.37 +/- 1.16 vs. -1.10 +/- 1.20, respectively; P < 0.05). The beneficial effect of bb genotype was independent of the prevailing PTH levels and was also observed in those patients with a baseline PTH level < 250 pg/ml (final Z score: bb, -0.42 +/- 1.3, N = 11; Bb/BB, -1.35 +/- 0.8, N = 11, P < 0.05). At the end of follow-up, the histomorphometric studies showed a higher bone formation rate adjusted for PTH levels in patients with the Bb or BB genotype than in those with the favorable bb genotype (0.29 +/- 0.06 vs. 0.21 +/- 0.08 micron3/micron2/day respectively; P < 0.05). In conclusion, high pretransplant PTH levels enhance the early trabecular bone loss after renal transplantation, and functionally different alleles of the vitamin D receptor gene may condition the bone turnover and the degree of recovery of the bone mass.

Adult↗
PubMed1996

Host cell invasion by trypanosomes requires lysosomes and microtubule/kinesin-mediated transport.

Invasion of mammalian cells by the protozoan parasite Trypanosoma cruzi occurs by an actin-independent mechanism distinct from phagocytosis. Clusters of host lysosomes are observed at the site of parasite attachment, and lysosomal markers are detected in the vacuolar membrane at early stages of the entry process. These observations led to the hypothesis that the trypanosomes recruit host lysosomes to their attachment site, and that lysosomal fusion serves as a source of membrane to form the parasitophorous vacuole. Here we directly demonstrate directional migration of lysosomes to the parasite entry site, using time-lapse video-enhanced microscopy of L6E9 myoblasts exposed to T. cruzi trypomastigotes. BSA-gold-loaded lysosomes moved towards the cell periphery, in the direction of the parasite attachment site, but only when their original position was less than 11-12 microns from the invasion site. Lysosomes more distant from the invasion area exhibited only the short multi-directional saltatory movements previously described for lysosomes, regardless of their proximity to the cell margins. Specific depletion of peripheral lysosomes was obtained by microinjection of NRK cells with antibodies against the cytoplasmic domain of lgp 120, a treatment that aggregated lysosomes in the perinuclear area and inhibited T. cruzi entry. The microtubule-binding drugs nocodazole, colchicine, vinblastine, and taxol also inhibited invasion, in both NRK and L6E9 cells. Furthermore, microinjection of antibodies to the heavy chain of kinesin blocked the acidification-induced, microtubule-dependent redistribution of lysosomes to the host cell periphery, and reduced trypomastigote entry. Our results therefore demonstrate that during T. cruzi invasion of host cells lysosomes are mobilized from the immediately surrounding area, and that availability of lysosomes at the cell periphery and microtubule/kinesin-mediated transport are requirements for parasite entry.

Amino Acid Sequence↗
PubMed1996

A porcine CD8+ T cell clone with heterotypic specificity for foot-and-mouth disease virus.

Foot-and-mouth disease virus (FMDV)-specific T cell lines and clones have been obtained from a swine lymphocyte antigen (SLA) inbred miniature pig vaccinated with chemically inactivated virus. One of the clones obtained, CE3, showed a specific and heterotypic proliferation against infectious but not inactivated FMDV in the presence of syngeneic peripheral blood mononuclear cells (PBMC). Adherent cells from PBMC were sufficient to support specific activation of the clone and the proliferation was abolished when the contact between CE3 and adherent cells was prevented. Phenotypic characterization of CE3 cells revealed expression of CD2, CD25 (interleukin-2 receptor), SLA class I and SLA class II. Furthermore, the cells were highly CD8 positive but showed low expression of CD4. The expression of T cell receptor (TCR) alpha and beta genes confirmed their T cell nature. Consistent with the CD8 phenotype, the proliferative response of CE3 was inhibited with MAbs to SLA class I and CD8. Altogether, these results indicate that CE3 is a porcine SLA class I-restricted CD8+ T cell clone, that recognizes a heterotypic FMDV antigen.

Animals↗
PubMed1996

Diversity of allergens causing occupational asthma among cereal workers as demonstrated by exposure procedures.

BACKGROUND: Occupational asthma among cereal workers is frequently due to cereals but other allergens can also be responsible. OBJECTIVE: We evaluated the allergens causing occupational asthma in the patients who had been diagnosed in our Department during the last 5 years. Specific bronchial reactivity to the implicated allergens was assessed and compared by standardized bronchial challenge. METHODS: Twenty-one patients (12 bakers, three millers and six farmers) were studied. We carried out in vivo tests (skin and challenge tests) and in vitro tests (specific IgE measurement) with cereals, enzymes, soyabean, storage mites and egg. A definitive diagnosis was established by means of specific bronchial provocation tests (BPT), except in three patients in whom it could not be carried out due to the severity of their asthma. In these cases the causative agent had to be determined by means of conjunctival challenge. RESULTS: Cereals were the main sensitizers among bakers (75%) and farmers (66%). Bakers were also sensitive to alpha-amylase (41%) and soyabean (25%), and farmers, to soyabean (33%) and storage mites (33%). Occupational asthma was due to cereals, soyabean and storage mites among millers. CONCLUSIONS: Besides cereals, other allergens such as enzymes, leguminous, egg and storage mites can be the causative agents of occupational asthma among cereal workers. Sensitization to different allergens in the different jobs is very likely due to differences in exposure.

Adult↗
PubMed1996

Annexin V autoantibodies in rheumatoid arthritis.

OBJECTIVE: To investigate the occurrence of anti-annexin V autoantibodies in sera of patients with rheumatoid arthritis to assess involvement with the disease and any relation to glucocorticoid treatment. METHODS: Anti-annexin V antibodies were measured by an enzyme linked immunosorbent assay (ELISA) which used the purified human recombinant protein as antigen. RESULTS: Concentrations of anti-annexin V autoantibodies, predominantly of the IgG class, were significantly raised in sera from patients with rheumatoid arthritis compared to normal controls. This was not correlated with other indices of disease activity such as erythrocyte sedimentation rate or C reactive protein and was unrelated to glucocorticoid treatment. CONCLUSIONS: Extracellular annexin V provides an antigenic stimulus for autoantibody production and its in vivo expression is independent of glucocorticoid control. Such autoantibodies may have a detrimental role in the arthritic condition by interfering with putative functions of annexin V, including collagen type II binding, inhibition of phospholipase A2 activity, and Fc receptor activity.

Adult↗
PubMed1996

[Effect of the treatment with amlodipine on left ventricular hypertrophy in hypertensive patients].

BACKGROUND: Left ventricular hypertrophy (LVH) is one of the physiopathological effects of hypertension and one of the main risk factors for sudden death, myocardial infarction and congestive heart failure. Drugs to treat hypertension must not only reduce blood pressure, but also modify the facts which lead to ventricular hypertrophy. This study has been designed to assess the effect of amlodipine, a calcium-antagonist, on LVH in hypertensive patients. METHODS: 20 hypertensive patients (mild to moderate, both sexes, mean age 45.0 yr) were included in a single-blind study. After an initial, four weeks placebo period, active treatment was given (amlodipine 5 mg a day). Dose titration was made after 4-8 weeks to 10 mg a day if necessary and continued until the end of the study. Systolic (SBP) and diastolic blood pressure (DBP), as well as pulse rate (PR) and adverse events were recorded at every visit. Blood and urine analysis, catecholamine, plasmatic renin activity and Mode M echocardiography were made at the beginning and the end of the study. RESULTS: Only one patient was excluded. SBP and DBP showed a significantly fall (p < 0.001). In 80% of patients DBP fell under 90 mm Hg. Every echocardiographic parameter, but left ventricular diastolic dimension, showed significantly reductions at the end of the study: septum thickness (p = 0.001), posterior wall thickness (p = 0.001), left ventricular systolic dimension (p = 0.014), wall relative thickness (p = 0.015), shortening fraction (p = 0.009), left ventricular mass (p = 0.001) and corrected left ventricular mass (p = 0.001). Blood parameters did not modify. CONCLUSIONS: Amlodipine has a beneficial effect on LVH and also is an effective and safe drug to treat mild to moderate hypertension.

Amlodipine↗
PubMed1996

Comparison of the cervical cytology test using the PAPNET method and conventional microscopy.

From August 1994 to June 1995, laboratories in 28 Mexican states and the Federal District submitted a total of 10098 diagnosed Pap test slides to Mexico's National Institute of Epidemiologic Diagnosis and Reference (INDRE) for reexamination by conventional methods and also by the automated PAPNET system in Suffern, New York, U.S.A. The aim was to determine the degree of agreement obtained by these various methods. Most of the slides examined (at least 78%) yielded negative results or merely indicated an inflammatory process; 8% to 14% indicated mild or moderate cervical dysplasia; and 2% to 3% indicated conditions ranging from severe dysplasia to invasive cervical cancer. Comparison of the state laboratory and INDRE diagnoses yielded a Kappa correlation coefficient of 0.62, near the lower limit of agreement, the agreement being poorest in cases where it was necessary to distinguish between degrees of abnormality. Although state laboratory underestimation appeared lowest with respect to cases of atypia and of mild, moderate, and severe dysplasia (between 12% and 20%), these percentages are alarming because it is at these stages that the patient may be treated to prevent evolution to carcinoma. While the Kappa correlation coefficient was better (0.80) when the INDRE and PAPNET diagnoses were compared, PAPNET showed only limited ability to distinguish between various pathologic alterations, and the percentages of underestimates (false negatives) obtained with PAPNET were also high. Overall, the results indicate a need to improve the quality of cervical cytology diagnoses at state public health laboratories in Mexico through stepped-up training and supervision. They also indicate that the use of PAPNET involves greater difficulty than does manual microscopic examination of cervical smears, and that a way still needs to be found to detect and review the false negative results generated by PAPNET before approving use of this technology.

Adolescent↗